Refuse compactor

ABSTRACT

Pantographic linkages of a refuse compacting ram assembly of a refuse compactor are driven through oppositely threaded screws acting on associated floating nuts captured in trunnions between the linkage and the nuts. Each nut is prevented from rotating with its screw by a key on the nut received in a key slot of a cover plate. Removal of the plates exposes the keys of the nuts. The keys can be wrenched to unloosen the nut. Removal of each of the nuts from the screws drops the pantographic linkage from its drive to facilitate repair of the compactor. A control circuit box containing the circuit elements for operator actuation is carried by a face panel and is electrically coupled to the operating circuits of the compactor through a male plug and and female plug receptacle so that upon removal of the face panel the control and operating circuits are unplugged without unwiring.

United States Patent 119 Mandrup REFUSE COMPACTOR [75] Inventor: Jorgen Mandrup, Eagle Rock, Calif.

[73] Assignee: Matador Industries, Inc., Temple City, Calif.

[22] Filed: Aug. 14, 1972 [21] Appl. No.: 280,533

[52] U.S. Cl. 100/229 A, 74/521, 100/52,

100/53, 100/287, 100/294, l5l/4l.76, 100/295 [51] Int. Cl B30b l/l8, B30b 15/14 [58] Field of Search l5l/4l.76, 41.7, 54;

85/32 K; 100/229 A, 24 S, 287, 289, 294, 295, 285, 53, 52; 74/521;254/122, 126

[ Oct. 22, 1974 Primary Examiner-Billy J. Wilhite Attorney, Agent, or FirmChristie, Parker & Hale 571 ABSTRACT Pantographic linkages of a refuse compacting ram assembly of a refuse compactor are driven through oppositely threaded screws acting on associated floating nuts captured in trunnions between the linkage and the nuts. Each nut is prevented from rotating with its screw by a key on the nut received in a key slot of a cover plate. Removal of the plates exposes the keys of the nuts. The keys can be wrenched to unloosen the nut. Removal of each of the nuts from the screws drops the pantographiclinkage from its drive to facilitate repair of the compactor. A control circuit box containing the circuit elements for operator actuation is carried by a face panel and iselectrically coupled to the operating circuits of the compactor through a male plug and and female plug receptacle so that upon removal of the face panel the control and operating circuits are unplugged without unwiring.

5 Claims, 7 Drawing Figures PAIENIEBIIBIZZIBM' macs REFUSE COMPACTOR BACKGROUND OF THE INVENTION The present invention relates to refuse compactors in general and, more in particular, to an improvement in refuse compactors which makes them readily serviceable in the field.

A refuse compactor is an appliance which applies force to trash, such as cans and bottles, to reduce the bulk of the trash. Accordingly, the space required for storing trash is reduced and trash handling is more convenient.

A refuse compactor employs a ram which is driven by some power means, typically an electric motor, to apply a crushing force on trash contained in a trash compartment, say a drawer.

One of the more attractive rams for refuse compactors employs a scissor jack or pantographic linkages for movement of a compaction head. A pair of oppositely threaded drive screws extend and retract the linkages.

As in most appliances, the operator control electrical SUMMARY OF THE INVENTION The present invention provides an improved refuse compactor of the type which employs parallel sets of pantographic linkages in its ram to extend and withdraw a compaction head from a refuse compartment. A pair of oppositely threaded coaxial drive screws are driven by power means such as an electric drive. Each screw is coupled, preferably, to the pantographic linkage through one of a pair of floating nuts captured in one of a pair of trunnions. The trunnions track on guides for movement along the axes of the screws. The nuts, being floating, are capable of limited angular displacement with respect to the axis of its screw to avoid thread seizure and damage to the threads. To prevent rotation of the nuts, each nut has a key received in a key slot of a member removably attached to the trunnion. The key is preferably defined by two parallel flats disposed on either side of the axes of screws and parallel to the axes of the screws.

When it is necessary to remove the pantographic linkages and compactor head from the drive, all that it is necessary to do is to remove the members having key slots from the trunnions, loosen the floating nuts by applying a wrench to the key flats, and then unthreading the nuts completely off the screws. This enables the trunnions to be slid off the screw and frees the interior of the compactor for maintenance or repair.

Preferably control electrical components are contained in a face panel wired to operating electrical components through a plug and plug receptacle between the interface of the face panel and the cabinet of the compactor such that upon removal of the face panel the control and operating circuits are electrically uncoupled without unwiring.

The compactor of the present invention, then, provides for rapid and facile removal of the ram from its drive to facilitate maintenance and repair. The uncoupling of the operator control circuitry from the operating circuitry further enhances the facility of the compactor for service.

These and other features, aspects and advantages of the present invention will become more apparent from the following description, appended claims and drawmgs.

BRIEF DESCRIPTION OF THE FIGURES along lines 2--2 of FIG. 1 showing the ram assembly in its retracted position;

FIG. 3 is a cross-sectional, elevational view similar to that of FIG. 2 showing the ram assembly in an extende position;

FIG. 4 is an exploded perspective view of a portio of the ram assembly illustrating in particular the improved trunnion and floating nut construction of the present invention;

FIG. 5 is an exploded perspective view illustrating in even more particular the improved trunnion and floating nut of the present invention;

FIG. 6 is a perspective, fragmentary view of the front panel of the refuse compactor of the present invention to illustrate the plug and plug receptacle coupling of the control electrical components and the operatinng electrical components; and

FIG. 7 is a line schematic illustratingan electrical circuit suitable for operation of the refuse compactor of the present invention.

DESCRIPTION OFTI-IE PREFERRED EMBODIMENTS With very brief reference to FIG. 1 a refuse compactor 10 has a cabinet with a top 12, sides 14 and a front 16. The front includes the face of a drawer l8 and a control panel 20. The drawer is for refuse.

With reference to FIGS. 2 and 3 the interior of the refuse compactor includes a ram 22 which in general is comprised of parallel sets of pantographic linkages 24, a compactor head 26 and a drive 28.

The drive includes an electric motor 30 which drives a gear reducer 32 which in turn drives a pair of oppositely threaded, coaxial screws 34 and 36. The screws are preferably of a common shaft. Screws 34 and 36 drive floating nuts 38 and 40, respectively. Floating nuts 38 and 40 are connected to the pantographic linkages through trunnions 42 and 44, respectively. The floating nuts and trunnions are in the upper portion of the cabinet behind front panel 20.

Operation of motor 30 in a directional sense causing floating nuts 38 and 40 to travel down screws 34 and 36 towards each other extends the pantographic linkages and lowers compactor head 26 into drawer 18 for the compaction of trash or refuse (see FIG. 3). Alternaages and compactor head to the position shown in FIG.

' As shown in FIGS. 1 and 6,.front control panel is removable and includes the controlsfor the electrical circuit of the refuse compactor, such controls including a key lock 46 and a switch 48. These controls are in electrical circuit with operating electrical circuitry within the cabinet of the refuse compactor.

If it is necessary to repair the refuse compactor, it typically will be necessary to remove the ram assembly. This requires removal of the pantographic linkages from the drive screws. Access to the drive screws, however, is limited.

Access to the drive screws must be had by removal of the front panel. The front panel, however, carries the control circuit elements, and its removal might require the unwiring of the connections between the front panel and the balance of the compactor. In accordance 6, the front panel is readily removable without disconnecting the wiring between the control circuit elements in the front panel and the balance of the circuitry in the cabinet by providing a male plug 50 in a control box 52,

in which box the control circuit elements are housed.

A cooperating female plug receptacle 54 is mounted in a box 56, in which many of the operating circuit elements are housed. Upon pulling the front panel from the balance of the compactor, plug 50 withdraws from plug receptacle S4 and unwiring is unnecessary.

As previously mentioned, it is often necessary in making repairs to the compactor to remove the ram assembly from its drive. This is done after the front panel is removed to expose trunnions 42and 44. The trunnions mount floating nuts 38 and 40 which are threadably received on drive screws 34 and 36, respectively. The floating nuts are captured within bores in each of the trunnions by a pair of plates 58 and 60. With the removal of the plates and the floating nuts from screws 34 and 36, the ram is freed from its drive.

The construction of the trunnions and floating nuts is best seen in FIG. 5. In the Figure, trunnion 42 and nut 38 are illustrated and their construction and relationship is the same as that of trunnion 44 and nut 40. Trunnion 42 has abore 62 for receiving nut 38. Bore 62 ends at a shoulder 64 against which nut 38 bottoms.

The bore and diameter of the nut allow angular misalignment between them to prevent the threads of the nut from binding on the threads of its screw when, for

example, the trash in the compactor is not evenly distributed and therefore causes uneven loading on head 26 of ram 22 which, in turn, will cause drive screws 34 and 36 to rotate slightly from their true axes. Plate 58 has a key slot 66 for receiving a key 68 of the floating nut. The key slot has parallel edges 70 and 72 for engaging mating parallel flats 74 and 76 of the key 68. Plate.58 is readily removable from trunnion 42 as by screws 78 and 80. The register of the key of the floating nut in the key slot of the plate prevents the floating nut from rotating with its screw and consequently causes the nut to travel up aand down the screw, depending on the direction of the rotation of the screw. When the plate is removed, the key of the nut is exposed and the nut can be removed. If the nut is tight, key 68 can be wrenched by using flats 74 and 76 as wrenching flats. After loosening, the nut can be manually removed.

Referring again to FIG. 2, the cabinet further includes a back wall 82 and a reinforced bottom wall 84 with the present invention and with reference to FIG. 4

having support legs 86. The cabinet is framed with four upright corner channels welded at the top to four angles 88 arranged in a rectangle and welded at the bottom directly to bottom wall 84 and short upstanding side walls formed integral with the bottom wall.

Referring to both FIGS. 2 and 3, a drawer 18 for receiving refuse is positioned within the lower portion of the cabinet. The drawer has an open top and it is formed by a U-shaped rear portion 91 and a front portion 92. The rear portion has a pair of reinforced side walls 93 formed integral with a back wall 94. Front panel 92 includes a front wall 95 and two integral side walls 97 which have tapered rear portions 99. Front portion 92 is mounted on'rear portion 91 to be pivoted forward a limited amount. Frontwall 95 is attached to the exterior panel of drawer 18. A bottom wall 96 closes the bottom of the drawer.

The front wall of the drawer is held in an upright powithdrawn on a conventional track and roller arrangement 104. A pair of angular brackets 106 are mounted to bottom wall 84 of the cabinet. Attached to each bracket is an outer channel of the track. It is preferred to have compaction loads transferred from the drawer to the bottom of the cabinet without loading the rollers of the track and rollers.

With reference to FIGS. 2, 3 and 4, ram 22 and its drive will be described. The ram includes an upper ram carrier channel 112 which is attached to upper framing angles 88. Rdm carrier channel 112 has two depending side walls 114, each of which is formed with a pair of elongated, horizontally extending slots 116 and 118.

With reference to FIG. 3, compactor head 26 also has a channel 120 supported parallel to channel 112 by pantographic linkages 24. The compactor head channel has a pair of upwardly extending short .side walls 122, each of which is formed with a pair of elongated horizontal slots 124. A flexible sealing plate 126 is secured to the lower side of the compactor head channel by a corrugated clamp plate 128.

Compactor head 26 is supported for vertical movement by means of force transmitting scissors-jack or pantographic linkages 24 formed by a series of pivotally connected arms and trunnions. More specifically, two upper arm pairs 130 and 132 on either side of gear box 32 are each pivotally connected by pivot pins 134. The upper ends of arm pairs 130 and 132 are pivotally connected to trunnions 42 and 44. The ends of the are completely positioned within the space between the rightand left-hand upper pantograph arms.

The heads of pivot pins 134 are confined within a pair of vertically oriented guide channels mounted on opposite sides of two opposed flanges extending downwardly from each side of carrier channel 112.

Two lower pairs of arms 138 and 140 are pivotally connected near their midpoints by a pivot pin 142. A trunnion 144 extends between and through the lower ends of arms 132 and the upper ends of arms 140. Pins 146 extend through the lower ends of arms 130 and the upper ends of arms 138. Using pins 146 at this location instead of a trunnion provides additional space for motor 30, as seen in F IG. 2. Thus the arms are properly spaced and pivotally connected.

It should be noted that pivot pins 134 are closer to the lower ends of arms 130 and 132 than to the upper ends. This provides increased leverage from the drive by increasing the mechanical advantage over a central disposition of the pins. Also, pivot pins 134 are offset on the lower side of a line 148 between the center of upper trunnion 44 and trunnion 144. Pins 134 are similarly located with respect to arm 130. Likewise, pivot pins 142 are offset below a line 150 on arms 138 between pins 146 and a lower trunnion 152. Pins 142 are similarly located with respect to arms 140. These features provide a greater force output from the ram during the initial downward movement of the ram from the fully retracted position.

The lower ends of arms 138 are joined by trunnion 152 and the lower ends of arms 140 are joined by a trunnion 154. The outer ends of the lower trunnions extend through elongated slots 124.

Pairs of rollers 156 are mounted on opposite ends of the trunnions 152 and 154 immediately within the side walls of the cabinet. These rollers engage channel 120 of the compactor head to facilitate movement of the arms and trunnions with respect thereto.

It will be appreciated that as drive screws 34 and 36 are rotated, force is transmitted through the arms and trunnions to drive the compactor head upwardly or downwardly depending upon the direction of rotation of the screws. During this movement, lower trunnions 152 and 154 move within elongated slots 124 and thereby guide the ram compactor head. To provide additional stability, a guide crank 160, seen in FIG. 3, is pivotally mounted at its midsection to channel 120. Guide crank 160 includes upwardly and outwardly extending end portions which extend through openings in arms 138. The guide crank is located and dimensioned such that it smoothly pivots with respect to arms 138 as the lower ends of the arms move within slots 124.

With reference to FIG. 7 the control and operating circuitry for the compactor will be described. Motor 30 may be energized by a conventional source of 120 volt AC indicated by leads I70 and 171. The circuitry includes start switch 48, either of the push button or toggle variety, which normally remains in the position indicated in the drawing but which can be held manually in the alternate position. Serially connected to switch 48 is a normally closed ram upper limit switch 174, a relay sensing coil 176, key switch 46, a drawer interlock switch 180, relay switches 182 and 183, armature winding 184 of motor and motor field 186, which in turn is connected to the other power lead 171. Connected across sensing coil 176 and motor windings 184 and 186 is a relay holding coil 188 and a normally open relay switch 190. Relay switches 182, 183 and 190 together with relay sensing coil 176 and holding coil 188 are available in a single relay component. The relay switches are shown in their normal position, when the relay coils are not energized. A normally open ram lower limit switch 192 is connected across motor armature 184. The second position of start switch 48 is connected across upper limit switch 174 and sensing coil 176.

Ram upper limit switch-174 is not physically shown in the drawings, but it should be understood that it may be conveniently mounted on the ram assembly to be opened when the ram is in its uppermost position. Similarly, normally open ram lower limit switch 192 may be conveniently mounted on the ram assembly to be closed when the ram reaches a lower limit position. Key switch 46 is accessible on front panel 20 of the cabinet as shown in FIG. 1. This switch is provided as a safety measure to prevent use of the appliance by those not authorized to have the key. Start switch 48 is also in the front panel. The male plug and female receptacle are not shown in FIG. 7. Drawer interlock switch is normally open and is depressed by the drawer when it is completely closed. Thus operation of the ram assembly is prevented if the drawer is in any position other than completely closed.

In operation of the compactor the drawer is withdrawn and an open top bag of suitable construction is positioned in the drawer with the top of the bag folded over the sides of the drawer. Refuse is then placed within the drawer and the drawer is returned to its fully closed position, as shown in FIG. 2. The ram is in its completely retracted position as shown in FIG. 2. With this condition, normally open drawer switch 180 is closed by the drawer, and the normally closed upper limit switch 174 is opened by the ram assembly.

If it is desirable to compact the refuse that has been placed in the drawer, key switch 46 is manually closed and the manual switch 48 is momentarily moved to its start position. This bypasses open upper limit switch 174 and energizes motor windings 184 and 186 through relay switches 182 and 183 which are positioned as shown in FIG. 7. This is the position for rotating the motor in the direction to drive the compactor head downwardly. Once the compactor head begins to move downward, upper limit switch 174 is released so that it is once more closed and thus the start switch 48 can be released so that the motor is energized through limit switch 174 and sensing coil 176.

The compactor head is driven into the open upper end of the drawer to compact the refuse in the drawer. As mentioned above, the elongated slots in the ram carrier and compactor head together with guide crank 160 guide the compactor head in its downward movement so that it remains essentially parallel to the ram carrier (horizontal).

As the refuse becomes more compressed making the force required for further compression greater, the motor draws more current. This additional current load is sensed by relay sensing coil 176. When the amperage load reaches a certain predetermined level, such as approximately 8 /2 amps, which corresponds to a predetermined load force by the ram, such as about 2,000 lbs., relay coil 176 will cause relay switches 182 and 183 to move to their lower or second positions and cause relay switch to close. It will be seen that moving switches 182 and 183 to their lower positions will cause the current flow through motor armature 184 to be reversed from that before the relay was opercurrent draw through the motor, with result that the amperage through the sensing coil is no longer sufficient to hold relay switches 182 and 183 in their lower position. However, they are held in their lower positions by holding coil 188 which remains energized by the closing of relay switch 190. Thus the motor continues to run in a reverse direction and the ram is retracted. When it is fully retracted upper limit switch 174 is opened, thus deenergizing the circuit. This causes the relay switches to return to their original condition, and the compactor is once more set to be operated.

In the event the motor is energized when there is no refuse in the drawer, it is possible that the ram assembly may damage the drawer structure before a sufficient load is developed that would cause the sensing coil to reverse operation of the motor. Thus as a safety measure, normally open lower limit switch 192 is closed by r the ram assembly when it reaches a predetermined lower or extended position. Closing this switch causes motor armature 184 to be bypassed with the result that the motor field draws a high amount of current. This increased amperage is sensed by relay coil 176 causing it to actuate relay switches 190, 182 and 183 in the manner previously described to reverse direction of the motor. Note that lower limit switch 192 will still be momentarily closed when the relay switches 182 and 183 are moved into their lower position, but that armature 184 is no longer bypassed with the relay switches in their lower position. Once the ram is retracted a small amount, lower limit switch 192 will of course automatically open.

What is claimed is: 1. An improved refuse compactor comprising: a. a cabinet; b. receptacle means in the cabinet for receiving refuse; I c. means for access to the receptacle means for placing refuse therein and for removing compacted refuse therefrom; d. a ram in the cabinet for compacting refuse having:

i. a compactor head for engaging and compacting refuse in the receptacle means;

ii. first and second sets of parallel and spaced apart pantographic linkages, each of the linkage sets having upper arms and lower arms, the lower arms of the linkage sets carrying the compactor head such that the lower arms of each linkage set can travel towards and away from each other;

iii. means for mounting the upper arms of the link age sets to the cabinet including first and second trunnions pivotally carrying the upper arms of the first and second sets of pantographic linkages, each of the trunnions having a bore ending in a shoulder on the interior end thereof;

iv. first and second nuts for the first and second trunnions, respectively, each of the nuts being received in the bore of its associated trunnion; and

v. first and second means for mounting the nuts on the respective trunnions for the transmission of a drive force in either direction along the axes of the nuts, for selective removal of the nuts from the trunnions, and to prevent rotation of the nuts, each of the mounting means including a plate removably secured to its associated trunnion and cooperating with the interior shoulder of the bore of such trunnion to keep the nut associated with such trunnion in such bore; and c. drive means for extending and retracting the pantographic linkage sets and to thereby extend and retract the compactor head into and out of the receptacle means, the drive including first and second oppositely threaded drive screws threadably receiving the first and second nuts such that with rotation of the screws in one direction the nuts travel towards each other to extend the pantographic linkage sets and rotation of the screws in the opposite direction of the screws in the opposite direction the nuts travel away from each other to retract the pantographic linkage sets. i r 2. The improved refuse compactor claimed in claim 1 wherein,

the first and second nuts each has a key at the outer end thereof; and

each of the plates includes a key slot receiving the key of its associated nut to prevent rotation thereof. I

3. The improved refuse compactor claimed in claim 2 wherein each of the trunnion bores and its received nut define a clearance between them for limited angular movement of the nut with respect to the bore.

4. An improved refuse compactor comprising:

a. a cabinet;

b. receptacle means in the cabinet for receiving refuse;

c. means for access to the receptacle means for placing refuse therein and for removing compacted refuse therefrom;

d. a ram in the cabinet for compacting refuse having:

i. a compactor head for engaging and compacting refuse in the receptacle means;

ii. first and second sets of parallel and spaced apart, extendible and retractable pantographic linkages carrying the compactor head;

iii. first and second trunnions pivotally carrying the upper arms of the first and second setsof pantographic linkages, the trunnions being mounted to the cabinet;

iv. first and second nuts for the first and second trunnions, respectively; and v. first and second means for mounting the nuts on the respective trunnions for the transmission of a drive force in either direction along the axes of the nuts, for selective removal of the nuts from the trunnions, and to prevent rotation of the nuts; and c. drive means for extending and retracting the pantographic linkage sets and to thereby extend and retract the compactor head into and out of the receptacle means, the drive including first and second oppositely threaded drive screws threadably receiving the first and second nuts such that with rotation of the screws in one direction the nuts travel towards each other to extend the pantographic linkage sets and with rotation of the screws in the opposite direction the nuts travelaway from each other to retract the pantographic linkage sets,

' the drive means also including a control circuit for manual operation and an operation circuit for the drive means proper, the control circuit being in a removable panel on the cabinet, the two circuits being electrically connected by a plug and plug receptacle at the interface between the removable panel and the balance of the cabinet for disconnecting and connecting the two circuits upon removal and installation of the removable panel, respectively.

5. An improved refuse compactor comprising:

a. a cabinet;

b, receptacle means in the cabinet for receiving refuse;

c. access means to the receptacle means for placing refuse therein and for removing compacted refuse therefrom;

d. a ram in the cabinet for compacting refuse having:

iv. means for mounting the upper arms of the linkage sets to the cabinet including at least one trunnion pivotally carrying corresponding of the upper arms of the linkage sets;

v. a nut associated with each trunnion; and

vi. means for mounting each nut on its associated trunnion for the transmission of a drive force in either direction along the axis of the nut, for selective removal of the nut from the trunnion, and to prevent rotation of the nut, the mounting means including a bore in each trunnion receiving the nut associated with such trunnion, each of the trunnion bores and its received nut defining a clearance between them for limited angular the linkage sets. 

1. An improved refuse compactor comprising: a. a cabinet; b. receptacle means in the cabinet for receiving refuse; c. means for access to the receptacle means for placing refuse therein and for removing compacted refuse therefrom; d. a ram in the cabinet for compacting refuse having: i. a compactor head for engaging and compacting refuse in the receptacle means; ii. first and second sets of parallel and spaced apart pantographic linkAges, each of the linkage sets having upper arms and lower arms, the lower arms of the linkage sets carrying the compactor head such that the lower arms of each linkage set can travel towards and away from each other; iii. means for mounting the upper arms of the linkage sets to the cabinet including first and second trunnions pivotally carrying the upper arms of the first and second sets of pantographic linkages, each of the trunnions having a bore ending in a shoulder on the interior end thereof; iv. first and second nuts for the first and second trunnions, respectively, each of the nuts being received in the bore of its associated trunnion; and v. first and second means for mounting the nuts on the respective trunnions for the transmission of a drive force in either direction along the axes of the nuts, for selective removal of the nuts from the trunnions, and to prevent rotation of the nuts, each of the mounting means including a plate removably secured to its associated trunnion and cooperating with the interior shoulder of the bore of such trunnion to keep the nut associated with such trunnion in such bore; and e. drive means for extending and retracting the pantographic linkage sets and to thereby extend and retract the compactor head into and out of the receptacle means, the drive including first and second oppositely threaded drive screws threadably receiving the first and second nuts such that with rotation of the screws in one direction the nuts travel towards each other to extend the pantographic linkage sets and rotation of the screws in the opposite direction of the screws in the opposite direction the nuts travel away from each other to retract the pantographic linkage sets.
 2. The improved refuse compactor claimed in claim 1 wherein, the first and second nuts each has a key at the outer end thereof; and each of the plates includes a key slot receiving the key of its associated nut to prevent rotation thereof.
 3. The improved refuse compactor claimed in claim 2 wherein each of the trunnion bores and its received nut define a clearance between them for limited angular movement of the nut with respect to the bore.
 4. An improved refuse compactor comprising: a. a cabinet; b. receptacle means in the cabinet for receiving refuse; c. means for access to the receptacle means for placing refuse therein and for removing compacted refuse therefrom; d. a ram in the cabinet for compacting refuse having: i. a compactor head for engaging and compacting refuse in the receptacle means; ii. first and second sets of parallel and spaced apart, extendible and retractable pantographic linkages carrying the compactor head; iii. first and second trunnions pivotally carrying the upper arms of the first and second sets of pantographic linkages, the trunnions being mounted to the cabinet; iv. first and second nuts for the first and second trunnions, respectively; and v. first and second means for mounting the nuts on the respective trunnions for the transmission of a drive force in either direction along the axes of the nuts, for selective removal of the nuts from the trunnions, and to prevent rotation of the nuts; and e. drive means for extending and retracting the pantographic linkage sets and to thereby extend and retract the compactor head into and out of the receptacle means, the drive including first and second oppositely threaded drive screws threadably receiving the first and second nuts such that with rotation of the screws in one direction the nuts travel towards each other to extend the pantographic linkage sets and with rotation of the screws in the opposite direction the nuts travel away from each other to retract the pantographic linkage sets, the drive means also including a control circuit for manual operation and an operation circuit for the drive means proper, the control circuit being in a removable panel on the cabinet, the two circuits being electrically connected by a plug and plug rEceptacle at the interface between the removable panel and the balance of the cabinet for disconnecting and connecting the two circuits upon removal and installation of the removable panel, respectively.
 5. An improved refuse compactor comprising: a. a cabinet; b. receptacle means in the cabinet for receiving refuse; c. access means to the receptacle means for placing refuse therein and for removing compacted refuse therefrom; d. a ram in the cabinet for compacting refuse having: i. a compactor head for engaging and compacting refuse in the receptacle means; ii. first and second sets of parallel and spaced apart pantographic linkages, each of the linkage sets having upper arms and lower arms; iii. means for carrying the compactor head by the lower arms of the linkage sets while permitting the lower arms of each linkage set to travel towards and away from each other; iv. means for mounting the upper arms of the linkage sets to the cabinet including at least one trunnion pivotally carrying corresponding of the upper arms of the linkage sets; v. a nut associated with each trunnion; and vi. means for mounting each nut on its associated trunnion for the transmission of a drive force in either direction along the axis of the nut, for selective removal of the nut from the trunnion, and to prevent rotation of the nut, the mounting means including a bore in each trunnion receiving the nut associated with such trunnion, each of the trunnion bores and its received nut defining a clearance between them for limited angular movement of the nut with respect to the bore in orthogonal planes containing the longitudinal axis of the bore; and e. drive means for extending and retracting the linkage sets and to thereby extend and retract the compactor head into and out of the receptacle means, the drive means including a threaded drive screw threadably receiving the nut such that with rotation of the screw in one direction the nut travels to extend the linkage sets and with rotation of the screw in the opposite direction the nut travels to retract the linkage sets. 